The adiabatic theory of greenhouse effect

Marathon-2005 Academician (RANS) OG Sorokhtin, Institute of Oceanology. Shirshov Sciences

The adiabatic theory of greenhouse effect The idea of heating the earth's atmosphere by greenhouse gases was first expressed in the late XIX century, the famous Swedish scientist Arrhenius S. [1] and since the obvious is taken for granted, with little or no verification [2-5]. This view is now completely dominates the conclusions of the Intergovernmental Panel on Climate Change (IPCC), Greenpeace, the UN Environment Programme (UNEP), World Meteorological Organization (WMO), as well as the withdrawal of Russian environmental and scientific organizations. The same view was fully supported by the decisions of international environmental conventions, in Rio de Janeiro (Brazil) in 1992 and in Kyoto (Japan) in 1997 is projected proponents of these ideas, by 2100, warming could reach 2.5 -5 ° C and cause sea level rise of 0.6 m -1, which already may be a problem for densely populated areas of the continental coasts, as well as for gas and oil production in lowland areas and most of the coasts of northern Russia. Projected, and other harmful consequences for the nature of global warming (the expansion of deserts, the disappearance of permafrost, soil erosion, etc.). Fears of similar catastrophic events, the pressure of environmental organizations, and often simply speculation on this subject makes governments of developed countries to allocate huge resources to fight the effects of global warming, allegedly linked to anthropogenic emissions to the atmosphere of "greenhouse gases". And how justified are these costs? Not if we're fighting "quixotic"? On closer acquaintance with this problem it turned out that the theory of greenhouse effect as such until the 90s. the last century did not exist, and all calculations of the effect of CO 2 and other greenhouse gases in the Earth's climate was carried out on different intuitive models with the introduction of numerous and not always stable parameters [4]. In this case the uncertainties in the estimates of various parameters of the model adopted (and they number at least 30) actually make the solution of the problem incorrectly. We decided to use a synergistic approach [6, 7] and an analysis of the most common positions, representing the Earth's atmosphere as an open dissipative (scattering power) system described by nonlinear equations of mathematical physics.

The main characteristics of the atmosphere The mass of the modern atmosphere is about 5.15. 1021 g, average air pressure at sea level, p 0 is the same physical environment, or 101.32 kPa, the density With high air pressure rapidly decreases exponentially (Fig. 1): (1) where g = 9,81 m / s 2 - acceleration due to gravity; - The average molar mass of atmospheric (K. gases (equal to 28.97 g / mol at p = 0), R = 1,987 cal / Mole) = 8.314. July 10 erg / (K. Mole) - gas constant, T - absolute temperature; h - the height above sea level. Accordingly, decreases with height and density of air.

Dry air contains 75.51% (by mass) of nitrogen, 23.15% oxygen, 1.28% argon, 0.046% carbon dioxide, neon, 0.00125% and about 0.0007% other gases. The important active component is water vapor (and water droplets in clouds): their average mass reaches 0.13. 10 20 g, equivalent to a layer of condensed water is 25 mm, an average of 2.5 g / cm 2. Considering the average annual evaporation and precipitation, which is approximately 780 mm of water column, it is easy to determine that the water vapor in the atmosphere is updated approximately 30 times a year, or every 12 days. In the upper atmosphere under the influence of solar ultraviolet radiation arises ozone (O 3.1. 10 15 g, while the oxygen 1.192. 10 21 g), this gas saving life 3). Despite the small amount (about on Earth from harmful solar radiation hard. We can distinguish three characteristic layer of atmosphere (Fig. 2) [8]. The bottom and most dense layer - the troposphere - which extends to a height of about 8-10 km in high latitudes and up to 1618 km in the equatorial belt (on average - up to 12 km), contains about 80% of the mass of the atmosphere and is characterized by a nearly linear distribution the temperature. The middle layer is essentially a rarefied atmosphere include the stratosphere and mesosphere and is characterized by a sharp maximum temperature reaching 270 K at an altitude of 50 km. Even higher is the thermosphere, in which the temperature of the ionized gas increases with altitude up to 1000 K or more, and at altitudes above 1000 km, the thermosphere is gradually transformed into the exosphere and beyond - into space. Between the troposphere and stratosphere, mesosphere and thermosphere are transition layers - respectively the tropopause (the temperature of about 190-220 K) and the mesopause (about 180-190 K).

In Fig. 2. The temperature distribution in the Earth's atmosphere: T e - radiation (effective) temperature of the Earth; T s - the average temperature on Earth, reduced to sea level; T - the value of the greenhouse effect; T bb - the temperature of a blackbody, orbiting the Earth In the troposphere, the temperature increases with height almost linearly, whereas in the upper atmosphere has a sharp maximum at an altitude of 50 km and rise to altitudes above 90 km. Maximum is associated with the absorption of ultraviolet solar radiation by ozone, increased due to the ionization of the rarefied air rigid solar radiation. Thus, in the stratosphere and mesosphere temperature is mainly determined by radiative heat transfer mechanism, whereas in the troposphere - the other processes, chief among which is the convective heat loss from the lower, dense layer in the stratosphere, where it lost to space by radiation already.

The adiabatic theory of greenhouse effect By definition, the greenhouse effect T is the difference between the mean surface temperature T s and its radiation (effective) temperature T e, under which the planet is visible from space: T = T s - T e. (2) The average temperature across the Earth as a whole is approximately equal to 288 K (+15 ° C), and its effective temperature is defined as follows: (3) where = 5.67. 10 -5 erg / (cm 2. With. K 4) - Stefan-Boltzmann constant, S - the solar constant at the distance of the planet from the Sun, A - albedo, or reflectivity, of the planet, largely controlled its cloud the cover. For the Earth, S = 1,367. June 10 erg / (cm 2. With), A 0,3, T e = 255 K (-18 ° C), and hence the greenhouse effect on Earth right now is +33 ° C. In terms of this definition the greenhouse effect is very real category, although the term greenhouse

effect is unsuccessful and physically just wrong. It is believed that the atmosphere contains socalled "greenhouse gases", weakly absorbs solar shortwave radiation, which for the most part reaches the earth's surface but delays the long-wave reradiated by this surface (thermal) radiation, thus greatly reducing heat transfer from Earth to space. This is taken as the main cause of increasing temperature. The higher the concentration in the air referred to "greenhouse gases", those considered to be more warming of the atmosphere. His name was on the effect of events in greenhouses covered with glass roofs (greenhouse effect), because the glass is too easily lets solar radiation in the visible spectrum, but delays the infrared. However, the main effect of greenhouses and polytunnels in the other - to prevent convective mixing filling their air with outside air, as soon as opening windows and greenhouses restored communication with the outside space, once lost, and the "greenhouse effect". Because the Earth has a relatively dense atmosphere, the bottom and most dense layer of her - the troposphere - the heat transfer is mainly due to convective motions of air masses, and not only on the mechanism of radiation - the radiation path, as it is imagined by proponents of the classical approach. Indeed, in the dense troposphere (pressure greater than 0.2 atm), the warm air mass expands and rises, and cold, on the contrary, shrink and fall. Radiative heat transfer is dominant only in the rarefied stratosphere, mesosphere and thermosphere. Hence the main conclusion: the average temperature distribution in the troposphere should be close to adiabatic, ie established with the expansion and cooling of air in its ascent, and, conversely, the compression and heating during lowering. (Specific distribution of temperature at specific points in time need not be adiabatic. We have in mind only the average distribution of time intervals of the order of months). In an adiabatic process is the absolute temperature by the equation [9] (assuming an ideal gas atmosphere): (4) where C - constant, p - pressure of the gas mixture c

p

and c

V

- Ratio of specific heats,

- specific (per unit mass) heat capacity of gas, respectively, at constant

pressure and constant volume. For all of triatomic gases (including CO

2

and H 2 O)

= 1.3,

=

0.2308, and for diatomic (N 2 and O 2) = 1.4, = 0.2857. The condensation of water vapor in the troposphere and the absorption of moisture, "greenhouse" gases, the infrared radiation is heat and rising temperatures. This leads to a change in . For example, the average value of this parameter for a wet, absorbing infrared radiation of the earth's troposphere is equal to 0.1905 [10], whereas for the dry air is 0.2846. It is important to note that the moisture in the troposphere generates clouds, which is the main factor determining the Earth's albedo. This creates a strong negative feedback between surface temperature and radiation, which leads to stabilization of the temperature regime of the troposphere (Fig. 3). Indeed, any increase in surface temperature increases evaporation and increases the cloudiness of the Earth, and this in turn increases the planetary albedo and reflectivity of the Earth's atmosphere. As a result of increased reflection of solar heat from the clouds into space, reducing its supply to the Earth, and the average surface temperature is reduced again to its previous level. Keep in mind that any negative feedback in the system leads to a linear response to output from the effects of the input [11]. This property is manifested regardless of the nature of the systems themselves, whether it is the planet's atmosphere, or the electronic amplifier Watt centrifugal governor.

When the input signal is the so-called blackbody temperature, which characterizes the heat of the body remote from the Sun to the Earth-Sun distance, only by the absorption of solar radiation (T bb = 278,8 K = +5,6 ° C for the earth), then mean surface temperature T s is linearly dependent on it. Consequently, the average temperature at any level of the Earth's troposphere (5) where b - a scale factor (if measurements are carried out in the physical atmosphere, the Earth for b = 1,186 atm-1). Since the average surface temperature of Earth is 288 K, then from (4) it immediately follows that at any level in the Earth's troposphere (at p> 0,2 bar) (6) where p 0 = 1 atm - atmospheric pressure at sea level (hereafter the subscript "0" marked the modern values of the parameters of the atmosphere). Equation (5) can be used in the case of other planets, if we consider the dependence of the StefanBoltzmann law: (7) Then for any planet with a dense (with p> 0,2 bar) atmosphere we (8) Dependence formula:

the composition and humidity of the atmosphere can be easily found by the known (9) (10)

where 29 g / mol - molar mass of air; = 76.49 kPa = 23.45 kPa = 0.046 kPa, p Ar = 1,297 kPa - the partial pressure of the gas [12]; p = 101,3 kPa - the total pressure of the

atmosphere, with

p

(N

2)

= 0.248 cal /

(g.

K), with

p

(O

2

) = 0.218 cal /

(g.

K), c

p

(CO

2)

= 0.197

cal / (g. K), with p (Ar) = 0,124 cal / (g. K) [13], with w and r - correction factor having the dimension of the specific heat and taking into account respectively the total heat effect of moisture condensation processes in a humid atmosphere (a w) and the absorption of thermal radiation of the Earth and the Sun (with r). If

p

= 0.2394 cal /

(g.

K) to dry the earth's atmosphere, then

= 0.1905 for wet and absorbing

infrared radiation of the atmosphere averaged with w + r = 0,1203 cal / (g. K). For planets with atmospheres of different nature under these parameters should be understood as characteristic of any thermal or chemical processes that lead to the release or absorption (with w + with r